TY - JOUR T1 - Disease-specific muscle oxygen transport and utilization during exercise in chronic obstructive pulmonary disease vs. chronic heart failure JF - European Respiratory Journal JO - Eur Respir J DO - 10.1183/13993003.congress-2022.1630 VL - 60 IS - suppl 66 SP - 1630 AU - J P Hartmann AU - R H Dahl AU - S Nymand AU - G Munch AU - C K Ryrsøe AU - B K Pedersen AU - P Thaning AU - S Mortensen AU - R M G Berg AU - U W Iepsen Y1 - 2022/09/04 UR - http://erj.ersjournals.com/content/60/suppl_66/1630.abstract N2 - Aim: We investigated muscle convective and diffusive oxygen (O2) transport in chronic obstructive pulmonary disease (COPD) compared with healthy controls (CON) and heart failure (HF) patients during one-legged knee-extensor exercise to determine disease-specific differences in peripheral determinants during exercise with a small muscle mass.Methods: Eight patients with moderate to severe COPD, eight patients with HF and eight age- and sex-matched controls were studied. We measured leg blood flow (LBF) by Doppler ultrasound during submaximal one-legged knee-extensor exercise, while sampling arteriovenous variables across the leg in all subjects during rest and exercise. The capillary oxyhemoglobin dissociation curve was reconstructed from paired femoral arterial-venous oxygen tensions and saturations, which enabled the estimation of O2 parameters in the capillaries of the contracting muscle.Results: Exercising LBF increased to a similar extent in HF (2.0(0.4) L/min) and CON (2.3(0.3) L/min), but was lower in COPD patients (1.8(0.3) L/min)(p<0.05). Muscle O2 extraction increased in COPD and CON during exercise (p<0,05), but not in HF. Muscle O2 consumption increased during exercise in all three groups, with no differences between groups, and the blood flow conductance (DO2) increased simirlarly, but when adjusting for flow, the DO2 was unchanged in the HF group.Conclusion: Disease-specific factors may play a role in peripheral exercise capacity in patients with COPD vs. HF. Thus, low convective O2 transport to contracting muscle seemed to predominate the exercise limitation in COPD, whereas muscle O2 diffusive capacity was blunted in HF.FootnotesCite this article as Eur Respir J 2022; 60: Suppl. 66, 1630.This article was presented at the 2022 ERS International Congress, in session “-”.This is an ERS International Congress abstract. No full-text version is available. Further material to accompany this abstract may be available at www.ers-education.org (ERS member access only). ER -